restroom
A public room with toilets and sinks for people to use.
A restroom is a polite term for a room with toilets and sinks, used especially in public places like restaurants, schools, stores, and offices. The word sounds more pleasant than saying “toilet,” which is why businesses and public buildings prefer it.
You'll see restroom signs everywhere: at the movie theater, the library, shopping malls, and airports. Schools often call them restrooms too, though students might say “bathroom” when asking for permission to go. Some places use other terms like lavatory (common on airplanes) or washroom (popular in Canada), but they all mean the same thing.
The word restroom is particularly American. It suggests a place where you can rest and freshen up, including using the toilet. That's why public restrooms usually have mirrors and sometimes even a separate area with chairs or benches. When traveling in other countries, you might need to ask for the “toilet” or “WC” (water closet) instead, since “restroom” isn't understood everywhere.